A data acquisition device for positioning and detecting arc intensity of a furnace electrode

Abstract

The utility model discloses a data acquisition device for space positioning of ore heating furnace electrode and arc intensity detection, including electromagnetic induction probe, vertical scanning executive mechanism, displacement detection unit and signal conditioning unit, vertical scanning executive mechanism installs on the furnace shell of ore heating furnace, and electromagnetic induction probe and displacement detection unit all install on vertical scanning executive mechanism, and can reciprocate along vertical direction with vertical scanning executive mechanism, and electromagnetic induction probe and displacement detection unit gather magnetic field signal and position information respectively, and output to signal conditioning unit, the utility model discloses through synchronous collection magnetic field signal and height position information, forms "height arc intensity" data sequence, and thereby can carry out the accurate positioning of electrode effective working end face.

Description

Technical Field

[0001] This utility model relates to process monitoring technology in the metallurgical industry, and in particular to a data acquisition device for an internal arc state sensing system suitable for submerged arc furnace equipment. This device can be applied to the operational monitoring of high-temperature submerged arc furnaces such as those for ferroalloys, industrial silicon, and calcium carbide, enabling transparent monitoring of energy distribution within the furnace. Background Technology

[0002] In the smelting process of an electric arc furnace, electrical energy is introduced into the furnace charge through electrodes, forming a high-temperature electric arc as the main heat source. The stability, length, and spatial distribution of the electric arc within the furnace directly affect the uniformity of the temperature field in the reaction zone, the raw material conversion efficiency, and the overall energy consumption level. However, because the electric arc furnace is a fully enclosed structure, the furnace environment is characterized by high temperature, high dust, and a reducing atmosphere, making it impossible to directly observe the arc morphology and the actual position of the electrode ends using traditional methods.

[0003] Currently, the industry generally relies on electrical parameters such as current, voltage, and power to indirectly determine furnace conditions, with operators adjusting electrode pressure and lifting actions based on experience. This "black box" control mode has significant limitations: Large errors in electrode insertion depth estimation can easily lead to excessively long or short electrode feeds; the working status of the three-phase electrodes is difficult to monitor synchronously, which can easily cause power imbalances; the lack of intuitive data support results in lagging control and affects product quality consistency; long-term operation can easily lead to higher flue gas temperatures, localized furnace lining erosion, higher power consumption, and frequent unplanned load control.

[0004] For electrode position detection inside a submerged arc furnace, existing technologies include indirectly calculating the electrode insertion depth by analyzing real-time power, electrode voltage, current, and active power parameters, thereby guiding the automatic adjustment of the furnace electrodes. Alternatively, hardware detection methods can be used, where a driven rod rotates to drive a fixed gear, causing a rotating shaft to rotate. The number and direction of the shaft's rotation are then used to detect the electrode's lifting height. However, while these technologies can detect the electrode's length or the distance it moves, they cannot accurately position the electrode at its actual working end face inside the furnace. Summary of the Invention

[0005] The purpose of this invention is to address the deficiencies in the existing technology and provide a data acquisition device that can effectively and precisely position the electrode on the working end face inside the submerged arc furnace by synchronously acquiring electromagnetic signals and height position signals generated by the electric arc in the furnace in real time.

[0006] To achieve the above objectives, this utility model employs a data acquisition device for spatial positioning of electrodes and detection of arc intensity in a submerged arc furnace, comprising an electromagnetic induction probe, a vertical scanning actuator, a displacement detection unit, and a signal conditioning unit; the vertical scanning actuator is installed on the furnace shell of the submerged arc furnace; the electromagnetic induction probe and the displacement detection unit are both installed on the vertical scanning actuator and can reciprocate along the vertical direction with the vertical scanning actuator; the electromagnetic induction probe and the displacement detection unit respectively acquire magnetic field signals and position information, wherein the magnetic field signals are output to the signal conditioning unit.

[0007] This invention generates a "height arc intensity" data sequence by synchronously collecting magnetic field signals and height position information, which enables precise positioning: when the arc signal at a certain height point reaches its maximum value, the coordinates of that point are recorded, which is the area with the strongest arc below the current electrode, representing the effective working end position of the electrode.

[0008] Furthermore, the electromagnetic induction probe is encapsulated in a high-temperature resistant insulating material, such as polytetrafluoroethylene, which has excellent high-temperature resistance, chemical corrosion resistance, and excellent electrical insulation. It can be used continuously at temperatures up to 120°C, making it suitable for the high-temperature environment around the furnace shell.

[0009] Furthermore, the aforementioned vertical scanning actuator adopts an electromechanical integrated device, including a servo driver, a ball screw, a guide rail, and a lifting rod; the servo driver is fixedly installed on the furnace shell of the electric arc furnace; the ball screw is connected to the output end of the servo driver and drives the lifting rod to reciprocate along the guide rail; the electromagnetic induction probe and the displacement detection unit are respectively fixedly installed on the lifting rod.

[0010] Furthermore, the displacement detection unit employs an incremental encoder or a non-contact magnetostrictive displacement sensor.

[0011] The current position of the lifting rod is synchronously collected by the displacement detection unit to ensure that the position information is strictly synchronized with the arc signal.

[0012] Furthermore, the aforementioned signal conditioning unit includes a signal isolator, a signal amplifier, a bandpass filter, an adjustable potentiometer, an ADC converter, an MCU processor, and an RS485 communication interface; the output signal of the electromagnetic induction probe is sequentially output to the PLC main control system via the signal isolator, signal amplifier, bandpass filter, adjustable potentiometer, ADC converter, MCU processor, and RS485 communication interface.

[0013] The weak analog signal is converted into a digital signal or a standard industrial signal by the signal conditioning unit and then output to the main control system.

[0014] Compared with the prior art, this utility model has the following advantages: by real-time synchronous acquisition of electromagnetic signals and height position signals generated by the electric arc in the furnace, it can effectively and accurately position the effective working end face of the electrode; based on this, a three-dimensional visualization view is generated, realizing the transformation of the electric arc state in the furnace from "invisible" to "visual", breaking the limitations of traditional experience-based furnace control.

[0015] This utility model device has a compact structure, is adaptable to high temperature and harsh environment, is easy to maintain and promote; and supports integration with smart factory systems, helping enterprises achieve digital transformation. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the data acquisition device for detecting the spatial positioning and arc intensity of electrodes in a submerged arc furnace according to this utility model. Figure 2 for Figure 1 A schematic diagram of signal processing from the arc induction probe output to the signal conditioning unit; In the diagram, 1-arc induction probe, 2-displacement detection unit, 3-vertical scanning actuator, 301-servo driver, 4-signal conditioning unit, and 5-PLC main control system. Detailed Implementation

[0017] The present invention will now be described in detail with reference to the accompanying drawings.

[0018] like Figure 1 As shown, the data acquisition device for electrode spatial positioning and arc intensity detection in a submerged arc furnace of this utility model includes the following components: 1) Electromagnetic Induction Probe 1: Employs an anti-interference electromagnetic induction sensor encapsulated in high-temperature resistant insulating material, with a maximum temperature resistance of 120℃, adapting to the high-temperature environment surrounding the furnace shell. It is used to capture the alternating electromagnetic field generated by the arc discharge at the electrode tip. Based on the randomness of the magnetic field direction, the electromagnetic induction probe can capture and acquire magnetic field signals from different directions. Electromagnetic Induction Probe 1 uses a multi-turn high-permeability magnetic core coil structure and an RLC low-pass filter circuit. The multi-turn high-permeability magnetic core coil has 40–100 turns, and the probe's frequency response range is 1 Hz–100 Hz. The cutoff frequency of the RLC low-pass filter circuit is 100 Hz, meeting the requirements for efficient capture of low-frequency magnetic field signals generated by the arc discharge at the electrodes of the submerged arc furnace.

[0019] 2) Vertical scanning actuator 3: An electromechanical integrated device consisting of a servo driver, a precision ball screw, a guide rail and a lifting rod, installed on the furnace shell; the precision ball screw is driven by a servo motor 301 to move the electromagnetic induction probe 1 vertically along the electrode axis (Z direction), with a stroke of 0–2000 mm and a speed of 50 mm / s.

[0020] 3) Displacement detection unit 2: It adopts an incremental encoder or a non-contact magnetostrictive displacement sensor with a resolution of 0.1mm. It uses an incremental encoder or a non-contact magnetostrictive displacement sensor to collect the current position of the lifting rod in real time and output it in the form of pulse sequence or analog current to ensure that the position information is strictly synchronized with the arc signal.

[0021] 4) Signal Conditioning Unit 4: Integrates a signal isolator, signal amplifier, bandpass filter (40~100Hz), adjustable potentiometer, ADC converter, MCU processor, and RS485 communication interface. The specific structure is as follows: Figure 2 As shown.

[0022] The signal conditioning process is as follows: S1) Signal isolator: Provides electrical isolation between input and output, preventing ground loop interference and high voltage intrusion from damaging downstream equipment. The signal isolator uses a DC-DC isolation module to supply power to the upstream and downstream stages separately, and the signal is transmitted through optocoupler isolation.

[0023] S2) Signal Amplifier: The raw signal output by electromagnetic induction probe 1 is a low-amplitude voltage in the millivolt range (mV), which is easily overwhelmed by system noise. Therefore, a high-precision, low-noise operational amplifier is first used to construct a non-inverting amplifier circuit for initial signal amplification. The instrumentation amplifier architecture features high common-mode rejection ratio (CMRR > 80dB) and low input offset voltage characteristics, effectively suppressing common-mode interference. The gain is configured via an external adjustable resistor, ranging from 2 to 15 times, to adapt to dynamic signal changes under different conditions, significantly improving the signal-to-noise ratio (SNR) and providing a stable input for subsequent processing.

[0024] S3) Bandpass filter: Due to severe interference, harmonics, and high-frequency switching noise at the electric arc furnace site, frequency-selective filtering of the amplified signal is required. This step uses a second-order active bandpass filter circuit, with the center frequency locked around 50Hz, the main energy frequency band of arc discharge, to accurately preserve the characteristic arc signal.

[0025] S4) Signal linearization / zeroing: Zero-point offset calibration is performed through an adjustable potentiometer, and full-scale calibration is achieved through hardware gain, thereby eliminating probe zero-point drift and ensuring that the output signal maintains a good linear correspondence with the arc intensity throughout the entire measurement range.

[0026] S5) ADC conversion captures the collected arc magnetic field strength signal at fixed time intervals, performs quantization by mapping the collected signal samples to finite discrete levels, and then converts the quantized level into binary digital output.

[0027] The S6 MCU processes the data, performing maximum, minimum, and average value processing on 10 consecutive sampling points to ensure high-fidelity acquisition of the arc intensity signal. Finally, the digital value is converted into the corresponding arc intensity value (unit: mV) according to the calibration curve and uploaded to the PLC main control system via the RS485 communication interface using the Modbus RTU protocol.

[0028] During testing, the system is set to automatically initiate a full furnace scan every 10 minutes (time interval adjustable). The PLC main control system sends motion commands to the servo driver, controlling the scanning mechanism to move the electromagnetic probe from the top dead center (…). Z = 2000mm) moves downwards at a constant speed to the lower stop point ( Z = 0mm); During the movement, the system synchronously collects two sets of data at a period of 100ms: the position signal from the displacement detection unit (in mm), and the conditioned arc intensity signal (in mV); the PLC performs a moving average filter on the collected "height-intensity" data sequence, removes outliers, and then uses a quadratic interpolation method to accurately locate the height coordinates corresponding to the maximum arc intensity. Using this coordinate position value, combined with the distance from the bottom of the scanning actuator to the furnace bottom, the actual insertion depth of the current working end of each phase electrode can be determined.

Claims

1. A data acquisition device for detecting the spatial positioning and arc intensity of electrodes in a submerged arc furnace, characterized in that, The data acquisition device includes an electromagnetic induction probe, a vertical scanning actuator, a displacement detection unit, and a signal conditioning unit. The vertical scanning actuator is installed on the furnace shell of the electric arc furnace. The electromagnetic induction probe and the displacement detection unit are both installed on the vertical scanning actuator and can reciprocate along the vertical direction with the vertical scanning actuator. The electromagnetic induction probe and the displacement detection unit respectively collect magnetic field signals and position information, and the magnetic field signals are output to the signal conditioning unit.

2. The data acquisition device according to claim 1, characterized in that, The electromagnetic induction probe is encapsulated in a high-temperature resistant insulating material.

3. The data acquisition device according to claim 1, characterized in that, The vertical scanning actuator includes a servo driver, a ball screw, a guide rail, and a lifting rod; the servo driver is fixedly installed on the furnace shell of the submerged arc furnace; the ball screw is connected to the output end of the servo driver and drives the lifting rod to reciprocate along the guide rail; the electromagnetic induction probe and the displacement detection unit are respectively fixedly installed on the lifting rod.

4. The data acquisition device according to claim 1, characterized in that, The displacement detection unit uses an incremental encoder or a non-contact magnetostrictive displacement sensor.

5. The data acquisition device according to claim 1, characterized in that, The signal conditioning unit includes a signal isolator, a signal amplifier, a bandpass filter, an adjustable potentiometer, an ADC converter, an MCU processor, and an RS485 communication interface; the output signal of the electromagnetic induction probe is sequentially output to the PLC main control system via the signal isolator, signal amplifier, bandpass filter, adjustable potentiometer, ADC converter, MCU processor, and RS485 communication interface.

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